This map includes a directory of the trail and highway markings that were used prior to the adoption of the highway numbering system. The numbers on the routes in the map correspond the the trail names in the index directory. Map scans courtesy of Terry Palmer.

The legend for this map also includes a trail marker directory, similar to the 1924 map. The red numbers on the maps correspond to the trail directory entries. Highways were also designated with the first generation of number designations, so many
highways had both a number designation and a trail marker. Humble Oil is now part of ExxonMobil. Map scans courtesy of Terry Palmer.

This map has detailed maps of cities. There is no indication of trail markers, so the trail marker system appears to be phased out by this time. This map also includes a map of the Texas Centennial Exposition at Fair Park in Dallas.
Map scans courtesy of Terry Palmer.

This map was published by the transit company, Dallas Railroad and Terminal, which provided bus and streetcar service. The main purpose of this map is to show the bus and streetcar routes. Map scans courtesy of Terry Palmer.

The 1942 highway system was dominated by the US Highway routes. There were no freeways in Texas in 1942; the first
freeway in Texas was Houston's Gulf Freeway in September 1948, and the first section of Central Expressway in Dallas opened on August 20, 1949. Humble Oil is now ExxonMobil

This map shows that by 1951, most of main route into Big Bend National park (then SH 227, now US 385) was paved. However, the map still shows an unpaved section inside the park.

1952 Austin Chamber of Commerce

The first item on the listing of points of interest on the cover (click on cover for larger view)
refers to "Zilker Springs". The description for Zilker Park also refers to Zilker Springs with the accompanying text "formerly Barton Springs".
So apparently the name was changed to Zilker Springs, and then back to Barton Springs.

This map shows the proposed alignments of many Fort Worth freeways, including the north-south freeway in west Fort Worth which was dropped from plans soon after this map was made. This map also shows an east-west route in Arlington between present-day I-20 and I-30. I had not seen that proposed alignment on any other map, but it would have been an eastward extension of the proposed East Rosedale freeway.

The inset map for Amon Carter field shows a proposed extension of the northwest-southeast runway to 12,000 feet. That proposal did not happen, and instead the north-south runway was extended (but not to 12,000 feet).

This view shows the planned alignment of the South Loop and the area that would become the Astrodome complex. Work on the Astrodome was underway around 1962. The original planned aligment of the South Freeway SH 288 is shown.

This map shows the planned route of the entire Beltway 8 Loop. It also shows the planned
southward extension of the West Loop, which was later cancelled and subsequently reinstated as the Fort Bend Parkway toll road.
In northeast Houston, the planned route of the US 90 Crosby Freeway is shown. That freeway inside BW 8 began construction in 2006 and
remains under construction in 2008.

This shows I-10 on the north side of downtown under construction. It opened on May 17, 1972. This map does
not show any work in progress on the missing link of US 59, which was just getting started in 1972.

The great freeway-building binge of the 1960s was over, but there were still plenty of
missing links and unbuilt freeways that would need to wait for funding in an era of greatly diminished resources for highway construction.
As highway construction slowed, my observation is that map companies updated their maps less frequently and therefore maps were more likely to have errors or be out-of-date.
However, this 1973 Exxon map is quite accurate.

This view shows the main population center of Texas and shows all interstates completed except for a section of I-20 west of Fort Worth. I-45 between
Dallas and Houston was completed in 1971. The last section of I-10 between Houston and San Antonio, from Waelder to TX 304, was completed in March 1972.